Differential pressure tools for plugging holes in well pipe

ABSTRACT

APPARATUS OR TOOLS FOR PLUGGING OR CLOSING HOLES, CRACKS, OR OTHER OPENINGS IN A CASING OR OTHER WELL PIPE, WHEREIN FLUID FLOW THROUGH THE HOLE CAUSED BY A DIFFERENTIAL FLUID PRESSURE BETWEEN THE INSIDE AND THE OUTSIDE OF THE PIPE IS UTILIZED FOR SEATING THE APPARATUS OVER THE OPENING, AND FOR INTRODUCING CLOSURE MATERIAL THROUGH THE OPENING FOR FORMING A PLUG OR CLOSURE THEREFOR.

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Oct. 26, 1971 L.. K. MooRE 3,614,988

DIFFERENTIAL PRESSURE TOOLS FOR PLUGGING HOLES IN WELL PIPE FiledJuly'so, `1969 4 sheets-sheet 1 TTORNE YS oct. 26, `1971 K, MOORE3,614,988

DIFFERENTIAL PRESSURE TOOLS FOR PLUGGING HOLES IN WFLL P'II'IEZ FiledJuly 50, 1969 4 Sl1eets-Shoot :r

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pmwef & Mafflw TTORNE YS L. K. MOORE Oct. 26, 1971 DIFFERENTIAL PRESSURETooLsEoE PLUGGING HOLES IN WELL PIPE 4 Sheets-Sheet .'5

Filed July 50, 1969 n '..Illr.

Zan/fvr@ /f Mao/e ATTORNEYS Oct. 26, 1,971 L. K. MOORE 3,614,988

DIFFERENTIAL PRESSURE TOOLS FOR PLUGGING HOLES N WELL PIPE Filed July30, 1969 4 SheetsSheot 4l OOQOO ,/5/25 OGOOO l00000 OOGOO b/-5/2 0OOO0ogOOo 00000 0 O00 00000 O000 (0o O0 00 U 0W/@06e ff. Moa/e i INI/ENTORnvm/ef f MaNLeu/A TTORNE YS United States Patent O 3,614,988DIFFERENTIAL PRESSURE TOOLS FOR PLUGGING HOLES IN WELL PIPE Lawrence K.Moore, 3716 Ingold, Houston, Tex.

Filed July 30, 1969, Ser. No. 846,203 Int. Cl. E21b 33/13 U.S. Cl.166-193 15 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTIONThe eld of this invention is apparatus for sealing or patching holes orother openings in casing or well plpe.

There are many situations in which holes, cracks or other openings occureither intentionally or accidentally, in well casing or other well pipe.For example, the hole may occur because of an intentional perforationusmg conventional perforating apparatus, or the hole, crack or otheropening may occur because of corrosion, a defect in the pipe or anunintentional puncturing of the pipe.

In the past, such openings in casing or well pipe have sometimes beenpatched with metal liners, such as lllustrated in U..S. Pats. Nos.3,167,122 and 3,191,677, but so far as is known, none have employed asealing material in liquid or semi-solid form which later solidiiies toeffect a seal or closure. Apparatus has been developed which rstperforates and then injects fluids through the perforations such asshownin U.S. Pats. Nos. 2,457,277 and 2,526,695, but none of such patentsdisclose the sealing of a hole in a pipe wherein a uid pressuredierential is used for the seating of the apparatus in the hole.

SUMMARY OF THE INVENTION This invention relates to apparatus for sealingor closing a hole, crack or other opening in a well casing or pipe. Withsuch apparatus, a fluid pressure dilerential between the inside and theoutside of the pipe to be sealed is utilized for locating a part of theapparatus in contact with the well pipe adjacent to the opening, andclosure material is introduced through the opening for forming a plug orclosure therefor.

BRIEF DESCRIPTION OF THE DRAWING FIG. l is a vertical sectional View,partly in elevation, of one form of the apparatus of this invention,illustrated in position in a well pipe or casing in proximity to a holeto be plugged or sealed using the apparatus of this invention;

FIG. 2 is a View similar to FIG. 1, but illustrating the apparatus withthe hole in well pipe or casing plugged or closed;

FIG. 3 is a bottom view of the apparatus illustrated -in FIG. 1;

FIG. 4 is an enlarged sectional view illustrating a portion of theapparatus of FIG. l in position in a hole in a well casing or pipe;

FIG. 5 is a vertical sectional view, partly in elevation, illustrating amodied form of the apparatus of this invention;

FIG. 6 is a sectional view of the apparatus of FIG. 5, taken on line 6 6of FIG. 5;

FIG. 7 is a vertical sectional view, partly in elevation,

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illustrating a further modification of the apparatus of this invention;

FIG. 8 is a vertical sectional view, partly in elevation, illustratingstill another modification of the apparatus of this invention in theposition it assumes during the lowering of same into a well pipe orcasing;

FIG. 9 is a view similar to FIG. 8, but illustrating such apparatus inposition -in a hole in a well pipe or casing;

FIG. 10 is a vertical sectional View of another form of the invention,illustrating the apparatus in a position during the lowering or droppingof same in a well pipe or casing;

FIG. 11 is a view of the apparatus of FIG. 10 after the apparatus hasmoved into sealing position in a hole in a well pipe or casing;

FIG. 12 is -a vertical sectional view, partly in elevation, illustratinganother form of the invention in position adjacent an opening in a pipeor casing to be plugged or closed;

FIG. 13 is a side view of a portion of the apparatus of FIG. 12illustrating the surface of the pipe engaging element adapted to bepositioned adjacent the opening in the pipe which is to be plugged orclosed;

FIG. 14 is a View similar to FIG. 13, but illustrating the pipe engagingelement of FIG. 12 in a different shape from that of FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the letter Adesignates generally one form of the apparatus of this invention whichis particularly illustrated Iin FIGS. 1-4. The apparatus A includes areceptacle 10 for holding a sealing material S. The receptacle 10 is iniluid communication with a mixing chamber 11 which forms a passagewaythrough a pipe engaging element 12 having a sealing surface 12a forsealing engagement with the -inside of the well pipe P surrounding anopening H. A ilexible head 15 is mounted outwardly of the pipe engagingelement 12 and such head 15 is adapted to be deformed or flexed enoughto pass through a hole or other opening H in the well pipe or casing P.Briefly, the receptacle 10 is provided with means such as pistons 20which are adapted to be actuated by fluid pressure or other suitablepressure to force the sealing material S from the receptacle 10 andoutwardly therefrom through suitable outlets 15a in each flexible head15 for depositing the sealing material S externally of the pipe Padjacent the hole H (FIG. 2) to thereby provide a closure or seal uponthe hardening or solidifying of same to prevent further ow of uidsthrough the hole H.

Considering the invention more in detail, the apparatus A may -belowered into the casing or well pipe P on a conventional wire line 21 orcable or any other suitable support. As illustrated in FIG. 1, the wireline or other support 21 is connected to a cap 22 which is threaded at22a or is otherwise connected to the upper end of the receptacle 10. Oneor more openings 22h are provided in the cap 22 for establishingcommunication between the exterior of the receptacle 10 and the area atthe upper end of such receptacle 10.

The receptacle 10 is preferably divided into two compartments 10a and10b by means of a central separator or partition 10c so that when thesealing material S is formed of two or more components, the componentsmay be kept separated from each other until it is desired to mix sameand inject them into the hole H. Each of the compartments 10a and 10bhas a piston 20 disposed therein with an annular seal ring 20a formed ofrubber or other suitable sealing material therewith.

'Each of the chambers 10a and 10b has an outlet or dis charge opening10d which establishes communication from the compartments 10a and 10b tothe mixing chamber 11 therebelow. The passages d are temporarily closedby disks 23 which are made of relatively thin aluminum, plastic, or anyother material which is capable of being ruptured or punctured `by theapplication of pressure thereto when the piston 20 moves downwardly inthe receptacle 10, as will be more evident hereafter. The disks 23 thuskeep the two compartments 10a and 10b isolated from each other so as tomaintain the components of sealing material S therein separated fromeach other until it is time to mix same together for injection into theholes H. By way of example, the sealing material S may be an epoxy resinand therefore each of the common components thereof are kept separatedin the two compartments 10a and 10b so as to maintain same in a liquidform until it is desired to inject them into the hole H where theybecome solidified due to their mixing and chemical reaction.

In the form of the invention illustrated in FIGS. 1 4, there are aplurality of the flexible heads (FIG. 3), the number of which may vary.In some instances, only a single flexible head 15 is employed, butusually, a plurality of such flexible heads 15 are employed since itfacilitates the movement of one of the heads 15 into the hole H to beplugged, as will be more evident hereafter.

Each of the flexible heads 15 is preferably constructed as illustratedin detail in FIG. 4. The flexible head 15 may be formed of rubber or aflexible plastic such as polyethylene or any other suitable materialwhich is capable of being deformed sufficiently to pass through the holeH. It is to be noted that the flexible head 15 is substantially conical,but it has a rounded nose 15b and the diameter of the rounded nose 15 issmaller than the diameter of the hole H into which such head 15 isintended to be inserted. On the other hand, the base 15e of the head 15is of a greater diameter than the diameter of the hole H so that theflexible head 15 must be compressed or squeezed down to a smallerdiameter to enable the base 15e and the other parts of a larger diameterthan the hole H to pass through the hole H in moving from the positionshown in FIG. l to that shown in FIGS. 2 and 4. Therefore, when the head15 reaches the position shown in FIGS. 2 and 4, the base 15e` re-extendsitself due to the flexibility of the material of the head 15 so that thebase 15e prevents or resists a return or withdrawal of the head 15through the hole H. The space between the base 15e and the inner surface12a of the pipe engaging element 12 is substantially equal to thethickness of the pipe P in the vicinity of the hole H so that when thehead 15 has passed through the hole H, the apparatus is essentiallylocked in position adjacent the hole H as shown in FIGS. 2 and 4.

A one-way check valve 25 which is urged to a closed position by a spring25a serves to permit the discharge of the sealing material S from themixing chamber 11 through a port 11a into the interior 15d of the head15, but it prevents the flow of fluid inwardly from the interior 15d ofthe head 15 into the mixing chamber 11. The sealing material isdischarged for the interior 15d of the head 15 through an outlet openingor openings 15a in the base 15e of the head 15 so that such sealingmaterial is deposited in the hole H and externally of the pipe P to forma mass around the element or head 15 and over the hole H so that uponthe hardening or solidifying of the material S, a plug or seal isprovided for the hole H.

To equalize the pressure acting upon the upper and lower ends of thecompartments 10a and 10b and therefore, the sealing material S therein,a flexible equalizing bag 26 is secured below the mixing chamber 11 andis in communication therewith through a port 11b. Thus, when theapparatus A is lowered into a well pipe P having a fluid therein, thepressure acting on the pistons will increase at the increasing depth ofthe liquid in the pipe P. Essentially the same pressure will also beacting upon the flexible bag 26, whereby there is an equalization ofpressure on the sealing material S during the lowering 4 and/or raisingof the apparatus A in the fluid within the well pipe P.

In the operation or use of the apparatus A of this invention, theapparatus A is lowered in the well pipe P on the wire line 21 or othersuitable support. The approximate depth of the hole H is known inadvance so that the apparatus A is first lowered to a point in proximityto such elevation and is preferably lowered below the hole H. During thelowering of the apparatus or tool A, fluid, such as Water or drillingfluid, is pumped from a conventional pump downwardly through the wellpipe P and outwardly through the hole H to the area externally of thepipe P. A fluid pressure differential thus exists or is created betweenthe interior of the pipe P and the area externally thereof, the extentof which depends upon the pumping pressure and well fluid conditions. Itis also possible to use a gas instead of a liquid for creating suchdifferential pressure, and as used herein, the term fluid includeseither a liquid or a gas for such operation. The operator notes thereading on the fluid pressure gauge at the surface during the loweringof the apparatus A so that he can compare it with subsequent readings,as will be explained.

The apparatus or tool A is moved downwardly to a point below the hole Hand then is moved slowly upwardly to a point above the hole H until oneof the flexible heads 15 comes close enough to the hole H to be forcedtherethrough by the fluid being pumped through the hole H. Since thepressure internally of the pipe P is greater than the pressureexternally thereof, the fluid is flowing outwardly through the hole H ata relatively high velocity, so that the fluid velocity acts to force theelement 12 towards the hole H to cause the surface 12a to seat aroundthe hole H and close off all or substantially all fluid flow through thehole H. It is to be noted that the sealing surface 12a preferablyconforms to the curvature of the inside wall of the pipe P (FIG. 3). Theclosest head 15 to the hole H is also caused to move towards same andonce the head 15 is in engagement with the hole H, the differential inpressure then acts against the pipe engaging element 12 and the othersubstantially vertically extending surfaces to force the head 15 throughthe hole H.

If only one of the heads 15 is employed on the apparatus A, theapparatus A may have to be turned or rotated as it is being raised andlowered to position the head 15 close enough to the hole H to enable theflowing liquid to force same through the hole H. However, where thereare a plurality of such heads 15 as shown in FIGS. 1, 2 and 4, thechances of one of such heads 15 entering the hole H are increasedsufficiently so that very little movement in a rotational direction, ifany, is required from the surface.

When the member 15 has been forced through the hole H to the positionshown in FIGS. 2 and 4, the operator at the surface will know that thishas occurred in two ways. First, the weight indicator on the wire line21 will show a change in the weight reading, the extent of which willdepend upon whether the tool was being raised or lowered when a head 15was forced through the hole H. Also, the pressure gauge for the fluidbeing circulated inside of the pipe P will show an immediate increase inpressure since the flow of the fluid through the hole H has been cut offor substantially cut off by the contact of the pipe engaging element 12with the inside surface of the pipe P. In any event, when one or both ofthe above indicators are noted by the operator, the movement of the wireline 21 by the operator is stopped and the pressure is allowed to reacha predetermined amount as indicated by the pressure gauge.

In the form of the invention illustrated in FIG. 1, the fluid Within thepipe P then serves to force the sealing material S outwardly from thereceptacle 10 through the single head 15 which has been inserted intothe hole H. The sealing material S is forced downwardly by the pistons20 which are forced downwardly by the fluid pressure acting thereon soas to initially rupture the disks 23. The sealing material S then flowsthrough the passages d into the mixing chamber 11 where it is mixedtogether. It should be noted that the mixing chamber 11 is preferablyinitially lled with a liquid such as a cleaning fluid or acid, and thebag 26 is preferably filled with the same liquid. The bag 26 collapses(FIG. 2) when the head 15 enters the hole H since the pressureinternally of the pipe P is greater than that externally of the pipe P.The cleaning liquid or acid is forced out through the ports or outlets15a of the single head 15 which is positioned through the hole H as thesealing material S is forced downwardly into the mixing chamber 11. Thecleaning agent or acid tends to clean the area around the head 15 in thehole H in advance of the distribution of the sealing material S aroundsuch head 15 to thereby provide a clean area for the epoxy resin orother sealing material to accumulate for subsequent hardening, It shouldbe noted that the heads 15 which do not go through the hole H remainclosed as the sealing material S is forced outwardly through the head 15which is in the hole H because those heads 15 which are still in thepipe P are subjected to the same pressure externally thereof as thepressure being exerted on the sealing material S. Since the pressureinternally and externally of such heads 15 in the pipe P is thussubstantially the same, the spring 25a in conjunction with each of theball valves 25 for such heads 15 keeps the ball valves 25 closed.However, as to the head 15 which has been inserted into the hole H, thespring 25a is not sufllciently strong to prevent the sealing material Sfrom forcing the ball 25 against the spring 25a and then forcing thesealing material S outwardly through the outlets 15a.

The tool A is left in position a sufficient time to permit the sealingmaterial S to harden or solidify into a mass forming a seal or plug suchas illustrated in FIG. 2. The particular length of the time requiredwill depend upon the type of resin or other material employed.

After the sealing material S has solidified, the apparatus A may bereleased from the head 15 and its pipe engaging element 12 which aredisposed in the hole or adjacent to the hole H. To effect such release,the wire line 21 is manipulated, using conventional jars, weights, orother means in any known manner for applying a severing force to thetube 11C of the mixing chamber 11. The external surface of the tube 11e`may be scored or otherwise provided with a break point to facilitate thebreaking of same at a particular spot inwardly of the element 12. Duringthe manipulation of the wire line 21, or the other action thereon foreffecting a shearing of the tool A from the part which is in the hole H,it is preferable to leave or maintain the pressure of the fluid withinthe pipe P to facilitate the holding of the element 12 and the partsoutwardly therefrom in the hole H, or adjacent to such hole H. After thetool A has been retrieved, it may be repaired or the parts replaced byany suitable means for a subsequent operation using the same tool A.

The operator will know at the surface of the well that the sealingmaterial S has properly and completely plugged the hole H because thepressure of the fluid within the pipe P will remain the same. If thehole H has not been properly plugged, the pressure of the fluid in thepipe P will gradually drop off. The pressure of the fluid within thepipe P may either be released or maintained while the tool is beingretrieved to the surface.

The effectiveness of the closure or seal S may also be tested fromexternally of the pipe P by developing a pressure externally of the pipeP which is greater than the hydrostatic pressure within the pipe P, andsuch testing can be effected in any known manner.

In FIG. 5, a modified apparatus A-1 is illustrated wherein the partswhich are similar to those of FIG. l have the same letters and/ornumerals. The receptacle 110 of the apparatus A-1 is formed with aflexible wall or cylinder of rubber, plastic or other similar material.

The cap 122 is preferably the same as the cap 22 Of FIG. 1 except thatit does not have the openings 22b. The cap 122 is preferably connectedto a closure plate 112a which is threaded thereto and which has theupper end of the receptacle secured thereto by a wire 30 or othersuitable attaching means. A partition 110C extends downwardly from andis preferably integral with the closure 122e so as to divide thereceptacle 110 into compartments l10n and 110b. Also, a perforatedcylinder Or tube 31 having openings 31a spaced longitudinally throughoutits length is disposed near the center of the receptacle 110 (FIG. 6),and such tube or cylinder 31 is preferably also secured or is formedintegrally with plate 122a.

The lower end of the receptacle 110 is preferably formed with a lowersection 110e which has a single port 110d in communication with the areainside of the tube 31, on both sides of the separator plate 110C. Thesection 110e is preferably formed integrally with the tubes 11C formingthe walls for the mixing chamber 11 and leading to each of the pipeengaging elements 12 and the flexible heads 15. The flexible bag 26 isdisposed below the mixing chamber 11 in the same manner as describedheretofore in connection with 21.

Semi-circular sealing disks 123 are disposed on each side of theseparator plate 110e near the bottom of the tube 31 for maintaining thesealing material S separated from cleaning fluid or acid within themixing chamber 11, passage 110d, and the flexible bag 26, until suchdisks 123 are ruptured.

The operation or use of the form of the invention A-1 illustrated inFIGS. 5 and 6 is substantially the same as that illustrated in FIG. 1 4except that the sealing material S is forced outwardly from thereceptacle 110 by the collapsing of the wall of the receptacle 110 toforce the contents thereof through the opening 31a and then downwardlyinto the mixing chamber 11 and outwardly through the flexible head 15which has been forced into a hole such as a hole H illustrated in FIG.2. The ports 31a permit the sealing material S which is in liquid formto move therethrough, but since the tube 31 is spaced from the separatorplate 110e as thus seen in FIG. 6, the collapsing of the wall of thereceptacle 110` cannot result in cutting off the discharge ofsubstantially all of the contents of the receptacle 110 through thedischarge opening 110b. When the sealing material S is an epoxy resinwhich has its two components separated, each of the components will bein one of the compartments 110a or 110b, but it will be appreciated thatif the material S is a liquid or a semi-liquid material which is asingle component and which sets by dehydration or other means afterbeing discharged from the apparatus A-1, it is not necessary to includethe separator 110e or the disks 123. The tube 31 might also beeliminated in such instance.

In FIG. 7, another form A-2 of the apparatus is illustrated wherein thereceptacle 210 has a single compartment with the sealing material Sbeing a single component material. For example, the sealing material Smay be an expandable cement slurry, a silicone rubber, or any othermaterial which is in a liquid or a substantially liquid form in thereceptacle 210 and which solidifies after being discharged through theflexible head 15 by dehydration, drying, or curing externally of thepipe P. It will be appreciated that the single component sealingmaterial S may be used in the other forms of apparatus illustrated inthis invention, and of course, it should also be understood that themulti-component sealing material of FIGS. 1 and 5 may be used in theapparatus of FIG. 7 by providing a separator therein in essentially thesame manner as illustrated in FIG. l. The piston 220 is a single pistonin the form shown in FIG. 7, and a single disk 223 is preferablyprovided. Only a single sealing head 15 may be employed with theapparatus of FIG. 7, although a plurality of such heads 15 such asillustrated in FIGS. 3 and 6 maybe employed in the FIG. 7 form of theinvention if so desired. The ball valve 25 is preferably omitted fromthe form of the invention shown in FIG. 7, in which case the flexiblebag 26 is also omitted. The discharge or forcing of the sealing materialS outwardly through the flexible head 15 after it has been positioned ina hole H in a pipe P in the same manner as illustrated in FIG. 2, isaccompanied by firing an explosive 35 above the piston 220. Theexplosive is a shotgun shell or other powder which is detonated by anelectrical spark from electrical wires 36 which extend to the surface ofthe well and are connected with a suitable source of electrical voltagefor creating the spark to ignite the explosive. The cap 222 is closed sothat the fluid does not enter the area above the piston 220, whereby theexplosive 35, is kept dry at all times.

The operation of the apparatus of FIG. 7 is essentially the same as thatillustrated and described in connection with FIGS. 1-4, except that theforce of the explosion from the explosive 35 is utilized for causing thepiston 220 to force the sealing material S downwardly and out throughthe openings in the flexible head 15 instead of using the fluid pressuredifferential within the well pipe. Thus, the apparatus A-2 is especiallyuseful when the differential pressure in a well pipe is insufficient toforce the sealing material S outwardly into the area externally of thepipe P. This might occur when the well formation pressure externally ofthe pipe P is high and therefore difficulties are encountered indeveloping a suflicient differential fluid pressure to drive the sealingmaterial S outwardly. It should be noted that since the apparatus A-2preferably has only a single flexible head 15, the support 221preferably is a wire line which has a rotating tool of knownconstruction thereabove (not shown) for rotating the apparatus A-2during the raising and lowering of same to thereby facilitate theinsertion of the head 15 into the hole H.

The form of the invention illustrated in FIGS. 8 and 9 is designated A-3in the drawings. Such apparatus A-3 has a receptacle 310 having aflowable material S therein which may together with the fluid in thehead 312 form a compound that hardens. A piston 320 is disposed in oneend of the cylinder or receptacle 310, and such piston 320 is exposed tothe fluid pressure in the well pipe P through an opening 322. The piston320 has an O-ring 32011 and a resilient snap ring 320b therewith. Theresilient snap ring 320b slides along the inside surface of the cylinderor receptacle 310 until the snap ring 320b is opposite an annular groove310f in the inside wall of the receptacle 310. At that point, the snapring 32017 is adapted to expand by the resiliency of the material of thesnap ring 320b and it enters the groove 3101 so as to thereafter lockthe piston 320 in the innermost position within the cylinder orreceptacle 310 (FIG. 9). The pipe engaging element 312 corresponds withthe pipe engaging element 12 of FIG. l, and it preferably includes aresilient layer 31211 of rubber, plastic or other material which formsthe surface for contacting the inner surface of the pipe P (FIG. 9). Thelayer of material 31211 may be formed integrally with the flexible head315 which has a hollow interior 31511 and which is in fluidcommunication with the receptacle 310 through an opening 31511. A ball325 together with a spring 32511 are disposed in the flexible head 316so that if a part of the material S is to be' separated from the otherpart, the ball 325 serves as a separator, whereby one component may bein the receptacle 310 and the other component may be in the interior31511' of the flexible head 315 (to the right of the ball 325 as viewedin FIG. 8).

The apparatus A-3 is lowered on a wire line or cable 321 whichpreferably is connected with a rotating tool of conventionalconstruction or any other suitable construc tion (not shown) so that theflexible head 315l may be moved to different positions to facilitate theinsertion thereof in a hole H such as shown in FIG. 9 of the drawings.The lower end of the cable 321 is secured to the receptacle 310 by aring 32111 which is welded, or otherwise secured to the housing orcylinder 310.

In the operation or use of the form of the invention illustrated inFIGS. 8 and 9, the apparatus is manipulated in the well in the samemanner as explained heretofore in connection with FIGS. 1-4 so that theapparatus A-3 is lowered below the hole H to be plugged and is raisedupwardly above such hole until such time as the differential fluidpressure in the well moves the flexible head 315 into the hole H. Afterthe resilient material 31211 on the pipe engaging element 312 has seateditself against the inside surface of the pipe P so as to initially closethe hole H the iluid pressure differential between the inside of thepipe P and the outside thereof is sufficient to force the piston 320from its original position (FIG. 8) to the right and thus to itsdischarged position (FIG. 9). The iluid in the cylinder or receptacle310 is discharged through the opening 31511 and it mixes with the fluidin the chamber or interior 315d of the flexible head 315. Since thepiston 320 forces a greater amount of fluid into the interior 31511 ofthe flexible head 315 than was initially therein, the flexible head 315is expanded or stretched so that it normally assumes a substantiallyglobular or spherical shape such as illustrated in FIG. 9 to accommodatethe additional material. The material S then preferably solidifies orhardens and because of the difference in the shape of the flexible head315 the diameter of the flexible head 315 is then greater than thediameter of the hole H to prevent the return of the ap paratus A-3 backinto the pipe P. The ball 325 serves as a closing means for closing thehole 31511 and it also facilitates the distortion of the flexible head315 to the enlarged shape as best seen in FIG. 9.

After the sealing material S has hardened within the enlarged head 315to substantially the shape shown in FIG. 9, `the apparatus A-3 may besevered at a suitable point such as a score line or ring 310g, and suchsevering can be accomplished by applying jarring forces to thereceptacle 310 through any conventional type of wireline jars or weightson the wireline 321.

In FIGS. 10 and 1l, a modified form of the apparatus A-4 `is illustratedand it is of a type which is adapted to be dropped in the pipe P withoutany cable or other supporting line. The device A-4 includes a receptacle410 which has two compartments 41011 and 410b which are interconnectedwith an opening 410e` having a ball 425 or other suitable movableclosure element between the cornpartments 41011 and 410b. Within thecompartments 41011 and 410b, the sealing material S is disposed, and itmay be of the epoxy type having two or more components which aremaintained separately from each other until such time as it is desiredto solidify same. The receptacle 410 is joined at an intermediate pointby a circular disk or plate 412 which also serves as a pipe engagingelement. The compartments 41011 and 41011 are filled by any suitablemeans. As illustrated in iFIG. 10, a passage 41211 extends from theouter edge of the element 412 inwardly to one side of the ball 425 forfilling the compartment 41011. After the compartment 41011 is filled,the passage 41211 is closed off by a suitable plug 412k. Another passage412e` establishes communication from the outer edge 412 t0 thecompartment 410b to the right of the ball 425, and it also has asuitable plug 412d for closing same after iluid fills the compartment410b. The element 412 is preferably a plate made of steel or relativelyheavy material as cornpared `to the receptacle 410 and the liquidsealing material S therein, so that when the apparatus A4 is dropped inthe fluid within a pipe P, it falls downwardly therein with the plate412 substantially vertically as shown in FIG. 10. The outer ends of thereceptacle 410 serve as the flexible heads 415, one of which is adaptedto fit within the hole H and the other end of which is collapsed asillustrated in FIG. l1 so as to discharge the contents from one end ofthe compartments 41011 or 41011 into the other of such compartments tomix the two components of the sealing material S together so as toenlarge the compartment in which the contents of the sealing material Sare finally disposed (FIG. ll) to a diameter which is greater than thediameter of the hole H. Therefore, after the sealing material S hashardened, the hole H is plugged or closed and the assembly A-4 isretained in position and cannot be dislodged therefrom.

In the operation or use of the apparatus of FIGS. l and 11, theapparatus A-4 is lowered or dropped in the fluid such as the well fluidwithin the pipe P. A differential pressure is created or exists acrossthe hole H which is to be plugged so that there is a greater pressureinternally of the pipe P than externally thereof. When the apparatus A-4reaches the vicinity of the hole H, the velocity of the fluid movingthrough the hole H draws and forces the apparatus to move towards suchhole H and the head 415 on one end of the compartment `410` movesthrough the hole H to bring one 'side of the p-ipe engaging element 412into contact with the inside of the pipe P' at which time substantiallyall of the flow of the fluid from the inside of the pipe P to the areaexternally thereof is cut off. When such condition occurs, the fluidpressure internally of the pipe P, being greater than that externally,causes a collapse of the receptacle 410 on the inside of the pipe P andthis initially forces the ball 425 Iinto the portion of the receptacle410 which is externally of the pipe P (FIG. 1l). Then, the por-tion ofthe sealing material S which is in the compartment 410a is forced orsqueezed through the opening 410e and lit mixes with the portion of thesealing material in the compartment A10-b so that they then are mixedtogether and react chemically to solidify into a solid. Due to theincreased amount of the material S within the compartment `410b afterthe contents of the compartment 410a have been forced into thecompartment 410b, the diameter of the compartment 410b is enlarged to adiameter greater than that of the hole H (FIG. 11) so that after thesealing material S has solidified it cannot return back into the pipe P.

Instead of dropping the apparatus A-4 by itself, a wire line carrier(not shown) may be used for connecting a plurality of such units A-4together at different points on the wireline carrier so that as each ofthe units A-4 enters a hole lit detaches itself from the wire and theremaining units A-4 'are then worked up and down in the well to seal orclose other holes or perforations until they are all plugged.

In the form of the invention illustrated in lFIGS. 12-l4, the apparatusA-S is essentially the same as that illustrated in FIG. and like partsbear like numerals, although it is shown as having only a singlecomponent sealing material S therein and therefore the dividing plate110C has been omitted.

In the form of the invention illustrated in FIGS. 12-14, the pipeengaging element 512 is utilized instead of the pipe engaging element 12and the flexible head 15 of FIGS. l and 5. The pipe engaging element 512may be of different configurations such as illustrated at the 512 and512 in FIGS. 13 and 14, and they are adapted to seal around holes,cracks, or openings H*1 of different shapes and configurations. The pipeengaging element 512 has a plurality of holes 512a distributed over itsinside surface which are surrounded by a sealing ring 512b. The sealingelement 512 also has holes 512a and a sealing ring 512b. The seal ring512b is Iadapted to t into sealing engagement with the inside surface ofthe pipe P around the crack, split, hole or other opening H-1 so as toseal off the fluid within the pipe P from such opening H-L When thisoccurs, the fluid pressure within the pipe P functions to squeeze thereceptacle wall 110- to force the sealing material S outward- 1y throughthe openings 512a so as to form a mass of the sealing material S in thehole H-l and just externally thereof for forming `a plug or closure forsuch hole H-l. A decentralizer which includes a spring 60 mounted on asupport bar or rod `61 suspended from the lower end of the apparatus A-Sis utilized for maintaining the element 512 in relatively closeproximity to the inside of the pipe P to facilitate its engagement andsealing around the opening H-1 when the element 512 is disposed inproximity to such opening H-1. The differential fluid pressure withinthe pipe P serves to effect the movement of the element 512 into contactwith the inside surface of the pipe P for such sealing engagementbetween the seal 512b and the inside of the pipe P. The apparatus A-5may be rotated by any suitable rotating tool to facilitate the locationof the element 512 over the hole or opening H-1.

The operation or use of the apparatus A-5 is essentially the same asthat described heretofore in connection with FIG. 1. Thus, theIapparatus A-5 is lowered and raised alternately and is preferably alsorotated until such time as the movement of the fluid from the inside ofthe pipe P to the area externally thereof forces the element 512 intosealing contact with the area surrounding the hole H-1. When thatoccurs, the differential in pressure of the fluid within the pipe P ascompared to that externally of the pipe P is sufficient to compress theflexible wall of the receptable and force the contents of thereceptacle, namely the sealing material S, outwardly through the chamber511 and then the openings 512a to the area externally of the hole H-1 inthe vicinity of same. The entire apparatus A-5 is permitted to remain inposition a sufficiently long time for the sealing material S to solidifyor harden and then the apparatus may be detached by pulling upwardly orjarring same downwardly. The element 512 may be detached with -the restof the apparatus A-5, or shear areas may be provided for severing theelement 512 olf from the rest of the apparatus so as to leave theelement 512 in position over the the opening Hel after the rest of theapparatus A-S is moved upwardly in the well.

Although the invention has been described with a flowable material orfluid for forming the closure or plug in the hole H, the invention isnot limited thereto since any material, such as deformable metals,inserted through the hole H for serving as a closure material for thehole H may be used.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made without departing from the spirit of theinvention.

What is claimed is:

1. Apparatus for closing an opening in a well pipe comprismg:

a pipe engaging element adapted to engage the inside wall of the wellpipe and adapted to be moved into position over said opening by the flowof fluid from 1nside of the well pipe through the opening in the wellpipe;

said pipe engaging element having a sealing surface for sealingengagement with the inside wall surrounding said opening in the wellpipe to substantially close off fluid flow through said opening; and

receptacle means with said pipe engaging element and having closurematerial therein for introduction through said opening to the areaexternally of said Well pipe for closing said opening.

2. The structure set forth in claim 1, wherein said sealing surface isflexible and including:

a plurality of discharge ports through which fluid flows for discharging-material through said opening and externally of said well pipe.

3. The structure set forth in claim 1, including:

means mounting said receptacle means on one side of said pipe-engagingelement;

a flexible head disposed on the other side of said pipe-engagingelement; and

passage means in said element for the flow of fluid from said receptaclemeans to said head after said head is disposed through said opening.

4. The structure set forth in claim 3, including:

a removable closure in said passage means to maintain the fluid in saidreceptacle means until discharged into said head.

5. The structure set forth in claim 1, including:

a flexible head having a diameter equal to or less than that of saidopening in the well pipe and adapted to extend through said opening',and

said head being adapted to be expanded to a diameter greater than thatof said opening in the well pipe while said head extends through theopening.

6. The structure set forth in claim 5, including:

a ball check valve inside of said flexible head for per- -mitting lluidto enter said head but for preventing the return thereof from said head.

7. The structure set forth in claim 5, including:

means for forcing material into said head from said receptacle means byiluid pressure in the well pipe after the pipe engaging element hasseated itself in engagement with the inside surface of the well pipe.

`8. The structure set forth in claim 7, wherein:

said means for forcing the sealing material into said head includes apiston in said receptacle means which is moved by fluid pressure in thewell pipe after the pipe engaging element has seated itself inengagement with the inside surface of the well pipe.

9. The structure set forth in claim 7, wherein said means for forcingmaterial into said head includes a pistion operable, by pressure in thewell pipe.

10. The structure set forth in claim 1, including:

a head adapted to enter the opening in the well pipe;

port means establishing fluid communication from said receptacle meansto said head; and

means for forcing the sealing material from said receptacle meansthrough said port means of said receptacle means after said head is insaid opening.

11. The structure set forth in claim 10, wherein:

the wall of said receptacle means is flexible and serves as said meansfor forcing the sealing material from the receptacle means when it issqueezed by the iluid pressure in the well pipe for discharging samefrom said receptacle means.

12. The structure set forth in claim 11, including:

means for separating said receptacle means into two compartments forthereby retaining two components of a sealing material separate fromeach other until discharged together from said receptacle means formixture and hardening in an area externally of the opening in the wellpipe.

13. The structure set forth in claim 10, including:

a plurality of flexible heads disposed at different radial positionsrelative to said receptacle means;

means establishing fluid communication between all of said flexibleheads and said receptable means; and

check valve means in each of said heads for preventing lluid in the wellpipe from entering any of said heads, but permitting an opening of theone of said heads which is subjected to a differential iluid pressurewhen it is in the opening in the well pipe.

14. The structure set forth in claim 10, wherein:

said means for forcing the sealing material from said receptacle meansincludes an explosive which is adapted to be detonated for providing aforce on said sealing -material to discharge same from said receptacle.

15. The structure set forth in claim 10, wherein:

said pipe engaging element is a disk which is disposed substantiallymid-way between said receptacle means and said head;

passage means are provided in said element for the tlow of material fromsaid receptacle means to said head; and

said passage means is closed by a removable closure until said flexiblehead enters said openng.

References Cited UNITED STATES PATENTS 2,933,136 4/1960 Ayers et al.166--284 3,292,700 12/1966 Berry 166-284 3,376,934 4/1968 Willman et al.166-284 X 3,379,251 4/1968 Bohn 166-286 3,399,726 9/1968 Harris et al.166-284 3,437,147 4/1969 Davies 166-284 DAVID H. BROWN, Primary ExaminerU.S. C1. X.R.

